Move hosting of Alerts and Config UIs from Nodejs to Spring Boot

Details

Description

The current UIs are served up by very lightweight nodejs applications, which serve the static bundle files produced by the angular build process, and proxies the rest api.

The proposal is to use a spring boot application, allowing us to harmonise the security implementation across the UI static servers and the REST layer, and to provide a routing platform for later microservices.

The UIs currently proxy to the REST API to avoid CORS issues, this will be achieved with Zuul.

Spring Security will also be extended to use a Knox SSO authenticator.